<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>js事件冒泡</title>

</head>

<body>

  <div id="divTop">
    <div id="div01">
      第一级子元素
    </div>
    <div id="div02">
      <div id="div0201">第二级子元素01</div>
      <div id="div0202">第二级子元素02</div>
    </div>
  </div>

  <script src="js/event.js"></script>

</body>

</html>